/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *    Obfuscate.java
 *    Copyright (C) 2002-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.filters.unsupervised.attribute;

import java.util.ArrayList;

import weka.core.Attribute;
import weka.core.Capabilities;
import weka.core.Capabilities.Capability;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.WeightedAttributesHandler;
import weka.core.WeightedInstancesHandler;
import weka.filters.Filter;
import weka.filters.StreamableFilter;
import weka.filters.UnsupervisedFilter;

/**
 * <!-- globalinfo-start --> A simple instance filter that renames the relation,
 * all attribute names and all nominal attribute values. For exchanging
 * sensitive datasets. Leaves string and relational attributes untouched.
 * <p/>
 * <!-- globalinfo-end -->
 * 
 * @author Len Trigg (len@reeltwo.com)
 * @version $Revision$
 */
public class Obfuscate extends Filter implements UnsupervisedFilter, StreamableFilter, WeightedAttributesHandler, WeightedInstancesHandler {

    /** for serialization */
    static final long serialVersionUID = -343922772462971561L;

    /**
     * Returns a string describing this filter
     * 
     * @return a description of the filter suitable for displaying in the
     *         explorer/experimenter gui
     */
    public String globalInfo() {
        return "A simple instance filter that renames the relation, all attribute names " + "and all nominal attribute values. For exchanging sensitive " + "datasets. Leaves string and relational attributes untouched.";
    }

    /**
     * Returns the Capabilities of this filter.
     * 
     * @return the capabilities of this object
     * @see Capabilities
     */
    @Override
    public Capabilities getCapabilities() {
        Capabilities result = super.getCapabilities();
        result.disableAll();

        // attributes
        result.enableAllAttributes();
        result.enable(Capability.MISSING_VALUES);

        // class
        result.enableAllClasses();
        result.enable(Capability.MISSING_CLASS_VALUES);
        result.enable(Capability.NO_CLASS);

        return result;
    }

    /**
     * Sets the format of the input instances.
     * 
     * @param instanceInfo an Instances object containing the input instance
     *                     structure (any instances contained in the object are
     *                     ignored - only the structure is required).
     * @return true if the outputFormat may be collected immediately
     * @throws Exception if
     */
    @Override
    public boolean setInputFormat(Instances instanceInfo) throws Exception {

        super.setInputFormat(instanceInfo);

        // Make the obfuscated header
        ArrayList<Attribute> v = new ArrayList<Attribute>();
        for (int i = 0; i < instanceInfo.numAttributes(); i++) {
            Attribute oldAtt = instanceInfo.attribute(i);
            Attribute newAtt = null;
            switch (oldAtt.type()) {
            case Attribute.NUMERIC:
                newAtt = new Attribute("A" + (i + 1));
                break;
            case Attribute.DATE:
                String format = oldAtt.getDateFormat();
                newAtt = new Attribute("A" + (i + 1), format);
                break;
            case Attribute.NOMINAL:
                ArrayList<String> vals = new ArrayList<String>();
                for (int j = 0; j < oldAtt.numValues(); j++) {
                    vals.add("V" + (j + 1));
                }
                newAtt = new Attribute("A" + (i + 1), vals);
                break;
            case Attribute.STRING:
            case Attribute.RELATIONAL:
            default:
                newAtt = (Attribute) oldAtt.copy();
                System.err.println("Not converting attribute: " + oldAtt.name());
                break;
            }
            newAtt.setWeight(oldAtt.weight());
            v.add(newAtt);
        }
        Instances newHeader = new Instances("R", v, 10);
        newHeader.setClassIndex(instanceInfo.classIndex());
        setOutputFormat(newHeader);
        return true;
    }

    /**
     * Input an instance for filtering. Ordinarily the instance is processed and
     * made available for output immediately. Some filters require all instances be
     * read before producing output.
     * 
     * @param instance the input instance
     * @return true if the filtered instance may now be collected with output().
     * @throws IllegalStateException if no input format has been set.
     */
    @Override
    public boolean input(Instance instance) {

        if (getInputFormat() == null) {
            throw new IllegalStateException("No input instance format defined");
        }
        if (m_NewBatch) {
            resetQueue();
            m_NewBatch = false;
        }
        push((Instance) instance.copy(), false); // No need to copy
        return true;
    }

    /**
     * Main method for testing this class.
     * 
     * @param argv should contain arguments to the filter: use -h for help
     */
    public static void main(String[] argv) {
        runFilter(new Obfuscate(), argv);
    }
}
